The United States plans to transfer about 4,000 of 19,000 marines stationed in Okinawa Prefecture to Guam over a period from 2024 to 2028, the head of the U.S. Pacific Command said Wednesday.

Adm. Harry Harris told a congressional hearing that "the movement of the bulk of the marines to Guam would occur in the 2024 to 2028 time frame."

Japan and the U.S. agreed in 2013 to start moving marines from Okinawa to Guam in the first half of the 2020s as part of efforts to reduce its footprint on the prefecture, which hosts the bulk of U.S. military bases in Japan.